Unlabelled: Soil health is the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans, and connects agricultural and soil science to policy, stakeholder needs and sustainable supply chain management. Historically, soil assessments focused on crop production, but today soil health also includes the role of soil in water quality, climate change and human health. However, quantifying soil health is still dominated by chemical indicators, despite growing appreciation of the importance of soil biodiversity, due to limited functional knowledge and lack of effective methods.
View Article and Find Full Text PDFThe role of soil organic carbon in global carbon cycles is receiving increasing attention both as a potentially large and uncertain source of CO emissions in response to predicted global temperature rises, and as a natural sink for carbon able to reduce atmospheric CO. There is general agreement that the technical potential for sequestration of carbon in soil is significant, and some consensus on the magnitude of that potential. Croplands worldwide could sequester between 0.
View Article and Find Full Text PDFTropical agroecosystems are subject to degradation processes such as losses in soil carbon, nutrient depletion, and reduced water holding capacity that occur rapidly resulting in a reduction in soil fertility that can be difficult to reverse. In this research, a polyphasic methodology has been used to investigate changes in microbial community structure and function in a series of tropical soils in western Kenya. These soils have different land usage with both wooded and agricultural soils at Kakamega and Ochinga, whereas at Ochinga, Leuro, Teso, and Ugunja a replicated field experiment compared traditional continuous maize cropping against an improved N-fixing fallow system.
View Article and Find Full Text PDFA wetland restoration demonstration project examined the effects of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacramento-San Joaquin Delta of California. Conversion of agricultural land to a wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) release from the peat soils, relative to the previous land use.
View Article and Find Full Text PDFAppl Environ Microbiol
November 1995
The assumption that carbon and soil water content are major determinants of microbial community structure and function is rarely questioned because of substantial evidence of the impacts of these variables on specific populations and functions. The significance of carbon and water for metabolic diversity at the microbial community level was tested on the field scale in agricultural plots varying in carbon inputs and in whether they were flooded. Surface soils in which rice straw was incorporated or burned and which were flooded or unflooded were sampled at monthly intervals three times during the flooded winter period (January to March) and again 1 month postdraining.
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